Electro-kinetic techniques and geotextiles for high water content sludge dehydration tests

Abstract

This study evaluates the use of Electro-Kinetic (EK) techniques and geotextiles to dehydrate high water content sludge obtained from a local watershed reservoir. A model test provided the de-hydration process for the high water content sludge using a geo-bag and electro-kinetic technique. Different electrode metal materials with various setups and different voltages were used in this study. The liquid limits and plastic index of the sludge mud are 33% and 10%, respectively. Geo-bags were made from a polyester multi-filament geotextile. The diameter and height of the geo-bags are 24 cm and 36 cm, respectively. The preliminary study indicated that PET geotextile geo-bag is a good filtration material for high water content sludge for dehydration applications. Steel and aluminum are very corrosive materials for this process. Low de-hydration rates were obtained using a copper rod as the anode electrode. Stainless steel is a corrosion resistance material with a good dehydration performance. Using a single stainless steel rod with 60V for EK dehydration process would reduce the water content from 100% to around 50% within 4-8 hours. The decrease in electrode distance with increasing number of electrodes would increase the dehydration process efficiency. The results from this study can be a valuable reference for developing geotextiles with electro-kinetic techniques for full scale sludge dehydration applications.